JPH08122052A - Profile measuring device - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a profile measuring device capable of accurately and efficiently measuring profile data. [Structure] Each thickness gauge (1, 2) inputs measurement data obtained by measuring the thickness of the object (20) at the same location for a certain period of time, and the thickness measurement (1, 2) A measuring instrument difference calculating unit (51) for obtaining the measuring instrument difference between the two and input measurement data in which each thickness gauge (1, 2) measures the thickness of the object to be measured (20) at a predetermined position after a certain time has elapsed Then, a calculation correction unit (52) that calculates the crown amount by correcting the measurement device difference from the measurement data is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a profile measuring device for measuring a cross-sectional shape (profile) of an object to be rolled such as a steel plate in a rolling process.

[0002]

2. Description of the Related Art In the process of rolling a rolled material such as a steel plate, the cross-sectional shape (profile) of the rolled material is measured. FIG. 5 is a block diagram of a conventional profile measuring apparatus used for such measurement.

As shown in the figure, the conventional profile measuring apparatus comprises a fixed thickness gauge 1 for measuring the thickness of a rolled material running at a high speed, that is, a central portion 21 of the object to be measured 20, and a width direction of the object to be measured 20. Scanning thickness gauge 2 for scanning and measuring the thickness of the object 20 in the width direction, fixed thickness gauge control unit 3 for controlling fixed thickness gauge 1 and scanning thickness gauge 2, and scanning thickness gauge control A profile calculation unit for calculating profile data of the object 20 by calculating measurement data of the thickness in the central portion 21 and the width direction input via the unit 4, the fixed type thickness gauge control unit 3 and the scanning type thickness gauge control unit 4. 5 and a display unit 6 for displaying the profile data.

First, the operation of scanning the entire width of the object 20 to be measured and obtaining the shape of the entire cross section (full width measurement mode) will be described.

First, the fixed thickness gauge 1 measures the thickness of the central portion 21 of the object to be measured 20, and outputs the measurement data to the fixed thickness gauge control unit 3. On the other hand, the scanning thickness gauge 2 scans the width of the DUT 20 (in the direction of the arrow in the drawing) to measure the thickness at each scanning point, and the measurement data is sent to the scanning thickness gauge control unit 4. Output. Profile calculation unit 5
Inputs the measurement data in the central portion and the measurement data in the width direction via the fixed type thickness gauge control unit 3 and the scanning type thickness gauge control unit 4 and obtains the difference between the two data, and the difference is, for example, 1 mm in width. It is converted into profile data for each, and the converted profile data is linearly interpolated and sent to the display unit 6. In this way, every time the scanning thickness gauge 2 scans the entire width of the measured object 20, the section (profile) of the newly scanned measured object 20 is displayed, for example, once a minute.

Next, the operation of continuously measuring the edge portion, not the entire width of the object to be measured (fixed point measurement mode) and obtaining the crown amount will be described with reference to FIGS. 5 and 6. FIG. 6 is for explaining the scanning positions of the fixed thickness gauge 1 and the scanning thickness gauge 2 when the DUT 20 is conveyed in the direction of the arrow.

First, in the profile computing unit 5 which receives a command from a host computer (not shown) to determine the crown amount in the fixed point measurement mode, the scanning thickness gauge control unit 4 causes the scanning thickness gauge 2 to measure the object 20 to be measured. A command is issued to move to a point 201 outside by a certain distance from the edge 23 of the. Upon receiving the command, the scanning thickness gauge control unit 4 sets the scanning thickness gauge 2 to the point 2
Move to 01. Next, the central portion 2 of the DUT 20 is previously measured.
The fixed thickness gauge 1 located on the extension line of 1 detects the presence of the object 20 to be measured, and this is determined by the fixed thickness gauge control unit 3
The profile calculation unit 5 is notified via. After detecting the object 20 to be measured, the profile calculation unit 5 activates the scanning thickness gauge control unit 4 after a lapse of a certain time, and moves the scanning thickness meter 2 from the point 201 to the edge portion 22 of the object 20 ( Point 202). The position of the edge portion 22 is stored in the profile calculation unit 5 in advance as a point that is displaced inward from the edge 23 of the measured object 20 by a predetermined distance.

After the scanning type thickness gauge 2 moves to the edge portion 22, the thickness at that point is measured and the measurement data is sent to the profile calculation section 5 via the scanning type thickness gauge control section 4. On the other hand, the fixed thickness gauge 1 continues to have the central portion 2
The thickness of No. 1 is measured, and the measurement data is sent to the profile calculation unit 5 via the fixed thickness gauge control unit 3. The profile calculator 5 calculates the crown amount C from the input measurement data as shown in the following equation (1).

C = Xc−Xe (1) Here, Xc represents the measurement data of the fixed-type thickness gauge 1, and X =
e indicates the measurement data of the scanning thickness gauge 2.

Next, the operation of continuously measuring the edge portion, not the entire width of the object to be measured (fixed point measurement mode) and obtaining the wedge amount will be described with reference to FIGS. 7 and 8. FIG. 7 is a block diagram of a conventional profile measuring device for obtaining the amount of wedge, and FIG. 8 is a fixed type thickness gauge 1 and a first scanning type thickness when the object 20 to be measured is conveyed in the arrow direction. Total 2
a and the scanning position of the second scanning type thickness gauge 2b.

Since it is necessary to measure the thickness at both ends (edge portions 22a, 22b) in the width direction of the object to be measured 20 in order to obtain the wedge amount, the first scanning type thickness gauge 2a and the second scanning type thickness gauge 2a are used. A thickness gauge 2b is provided, and a first scanning type thickness gauge control section 4a and a second scanning type thickness gauge control section 4b are provided to control them, and first and second scanning type thickness gauge controls are provided. The sections 4a and 4b are respectively profile calculation section 5
It is connected to the.

As shown in FIG. 7, a first scanning type thickness gauge 2
a is the thickness of the drive-side edge portion 22a of the object to be measured 20, and the second scanning thickness gauge 2b is the object to be measured 20.
The thickness of the edge portion 22b on the operator side is measured.

The operation for obtaining the wedge amount will be specifically described below.

The profile calculation unit 5 which receives a command from the host computer (not shown) to obtain the wedge amount in the fixed point measurement mode activates the first scanning type thickness gauge control unit 4a to make the first scanning type thickness. The total point 2a is located at a point 20 outside the drive side edge 23a of the DUT 20 by a certain distance.
1a and activates the second scanning type thickness gauge control unit 4b to move the second scanning type thickness gauge 2b from the edge 23b on the operator side of the object to be measured 20 at a predetermined distance 2
Control to move to 01b. Next, the fixed-type thickness gauge 1 that was previously positioned on the extension line of the central portion 21 of the measured object 20 detects the presence of the measured object 20, and this is detected by the fixed-type thickness gauge control unit 3. The calculation unit 5 is notified. The profile calculation unit 5 activates the first scanning type thickness gauge control unit 4a when a certain period of time has elapsed after detecting the measured object 20, and the first scanning type thickness gauge control unit 4a causes the first scanning type thickness gauge control unit 4a to operate. 2a is the edge 2 on the drive side of the DUT 20
2a (point 202a), the second scanning type thickness gauge control unit 4b is activated, and the second scanning type thickness gauge control unit 4 is activated.
b moves the 2nd scanning type thickness gauge 2b to the edge part 22b by the side of the operator of the to-be-measured object 20 (point 202).
b). The positions of the two edge portions 22a and 22b are stored in advance in the profile calculation unit 5 as points that are displaced inward from the edges 23a and 23b of the device under test 20 by a predetermined distance.

The first and second scanning type thickness gauges 2a and 2b measure the thicknesses of the points after reaching the edge portions 22a and 22b, respectively, and the respective measurement data are controlled by the first and second scanning type thickness gauges. It is sent to the profile calculation unit 5 via the units 4a and 4b. The profile calculator 5 calculates the wedge amount W from the two input measurement data as shown in the following equation (2).

W = Xo−Xd (2) Here, Xo is the measurement data of the first scanning thickness meter 2a, and Xd is the measurement data of the second scanning thickness meter 2b.

By the way, the above-mentioned fixed type thickness gauge 1, scanning type thickness gauge 2, and first and second scanning type thickness gauges 2a, 2 are provided.
b has its own measurement error. Therefore,
In order to correct the measurement error peculiar to each, the same sample material as the object to be measured is measured offline, and the measurement error peculiar to each thickness gauge is measured in advance. The measurement error is corrected.

However, even if the thickness of the object to be measured is measured online after measuring the measurement error, each thickness gauge causes a measurement error within ± 0.1% of the thickness of the object to be measured. Therefore,
The crown amount and the wedge amount obtained by the above equations (1) and (2) may each include an error within ± 0.2%. This means, for example, that the thickness of rolled material is 10
If it is mm, it means that an error of up to 20 μm can occur, and an error of this magnitude cannot be ignored.

In order to deal with this, conventionally, a measurement error (hereinafter referred to as a measuring instrument difference) between the thickness gauges is obtained in advance in advance, and the profile computing section corrects the measuring instrument difference when offline. It was

[0020]

However, in this method, since the measuring instrument difference between the respective thickness gauges differs depending on the thickness of the object to be measured, when the measuring range of the object to be measured is online, the offline is beforehand performed. Even at that time, it is necessary to measure the difference between the measuring instruments over the entire area, which is a problem that it takes time. Furthermore, since each thickness gauge itself deteriorates due to mechanical wear or the like, it is necessary to periodically update the measurement machine difference stored in the profile calculation unit, which is not efficient.

Therefore, an object of the present invention is to provide a profile measuring apparatus capable of accurately and efficiently measuring the profile data of the object to be measured.

[0022]

A profile measuring apparatus according to claim 1 of the present invention is a profile measuring apparatus for measuring the thickness of a central portion of an object to be measured, and the thickness of an edge portion of the object to be measured. And a second thickness gauge for measuring the profile of the object to be measured based on the measurement data of the first and second thickness gauges. Meter to measure the thickness of the same portion of the object to be measured for a certain period of time, and after the elapse of a certain time, the first thickness meter measures the thickness of the central portion of the object to be measured and the second thickness meter to the object to be measured. The first thickness gauge and the second thickness are measured from the control means for controlling the thickness of the edge portion of the first thickness gauge and the measurement data measured by the first thickness gauge and the second thickness gauge for a certain period of time. The measuring machine difference calculation unit for obtaining the measuring machine difference between the gauges, and the first thickness gauge and the By correcting the measuring difference from the measurement data measured by the thickness meter is that a profile calculating means and a calculation correction unit for calculating the amount of the crown.

The profile measuring apparatus according to claim 2 of the present invention comprises: a first thickness gauge for measuring the thickness of the central portion of the object to be measured; and a first thickness meter for measuring the thickness of the edge portions on both sides of the object to be measured. A profile measuring device having a second and a third thickness gauge and measuring a profile of an object to be measured based on measurement data of the first to third thickness gauges. The thickness gauge at the same location of the object to be measured for a certain period of time, and after a certain period of time, the first thickness meter measures the central portion of the object to be measured, and the second and third thickness meters measure the thickness. The first thickness gauge and the second thickness gauge are determined from the control means for controlling the edge portions on both sides of the object to be measured and the measurement data measured by the first, second, and third thickness gauges for a certain period of time. First measuring instrument difference between the thickness gauges and the first thickness gauge and the third thickness And measuring the difference calculation unit for obtaining a second measuring difference between total mutual, fixed time first after a lapse of a second, and a third from the measurement data measured by the thickness meter first
And a profile calculation unit having a calculation correction unit that calculates the crown amount and the wedge amount by correcting the second measuring machine difference.

[0024]

In the profile measuring apparatus according to the first aspect of the present invention, first, the first thickness meter and the second thickness meter measure the thickness of the same portion of the object to be measured for a fixed time, and the respective measurement data are obtained. It is sent to the measuring machine difference calculation section of the profile calculation section. The measuring instrument difference calculation unit obtains the measuring instrument difference between the respective thickness gauges from this measurement data. After a certain period of time, the first thickness meter moves to the center of the object to be measured and the second thickness meter moves to the edge of the object to measure the crown amount. Measure the thickness of the object. The calculation correction unit of the profile calculation unit inputs the measured data, corrects the measuring machine difference calculated by the measuring machine difference calculating unit, and calculates the crown amount.

Thus, the crown amount can be measured accurately and efficiently.

In the profile measuring apparatus according to claim 2 of the present invention, first, the first thickness gauge, the second thickness gauge, and the third thickness gauge measure the thickness at the same location of the object to be measured for a predetermined time. Then, each measurement data is sent to the measuring machine difference calculation unit of the profile calculation unit. From the measurement data, the measuring instrument difference calculation unit determines the first measuring instrument difference between the first thickness gauge and the second thickness gauge and the second measurement between the first thickness gauge and the third thickness gauge. Find the machine difference. After a certain period of time, the first thickness gauge moves to the center of the object to be measured in order to obtain the crown amount and the wedge amount, and the second thickness meter and the third thickness meter are arranged on both sides of the object to be measured. Move to each edge and measure the thickness of the object to be measured at each moving location. The calculation correction unit of the profile calculation unit inputs the measured data, corrects the first and second measuring machine differences obtained by the measuring machine difference calculating unit, and calculates the crown amount and the wedge amount.

Thus, the amount of crown and the amount of wedge can be measured accurately and efficiently.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the profile measuring apparatus of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing this embodiment, and FIG. 2 explains the scanning positions of the fixed type thickness gauge 1 and the scanning type thickness gauge 2 of this embodiment when the object 20 to be measured is conveyed in the direction of the arrow. It is for doing. The present embodiment is for obtaining the crown amount, and its configuration is different from that of the conventional profile measuring device (see FIG. 5) in that the profile calculating unit 5 includes a measuring machine difference calculating unit 51 and a calculation correcting unit. And 52 are newly provided.

In FIG. 2, the fixed-type thickness gauge 1 always measures the central portion 21 of the object 20 to be measured, as in the conventional case.
It is located on the extension line of 1, that is, in the center of the rolling line.
On the other hand, before the measurement, the scanning type thickness gauge 2 is also located at the center of the rolling line like the fixed type thickness gauge 1 (point 100).

When the object 20 to be measured plunges into the point 101 in this state, the fixed thickness gauge 1 detects the object 20 to be measured and notifies the profile calculator 5 via the fixed thickness gauge controller 3. To do. At the same time, the fixed thickness gauge 1 measures the thickness of the central portion 21 of the DUT 20, and transmits the measurement data to the measuring machine difference calculation unit 51 of the profile calculation unit 5 via the fixed thickness gauge control unit 3. . Similarly to the fixed type thickness gauge 1, the scanning type thickness gauge 2 also measures the thickness of the central portion 21 of the object 20 to be measured, and the measured data is measured by the measuring device of the profile calculation section 5 via the scanning type thickness gauge control section 4. It is transmitted to the difference calculator 51. The measuring instrument difference calculator 51 receives a notification from the fixed thickness gauge 1 that the object 20 to be measured is detected until a predetermined time elapses, that is, while the object 20 to be measured is in the section d in FIG. The measurement data is continuously received from the fixed thickness gauge 1 and the scanning thickness gauge 2. The measuring instrument difference calculator 51 averages the measured data and calculates and stores the measuring instrument difference dX of the fixed type thickness meter 1 and the scanning type thickness meter 2 as shown in the following expression (3).

DX = Xs−Xf (3) Here, Xs is an average of the measurement data of the scanning thickness gauge 2, and is an average of the measurement data of the fixed thickness gauge 1 of Xf.

Next, the profile calculation unit 5 activates the scanning type thickness gauge control unit 4 when the certain time has passed (point 103 in FIG. 2), and the scanning type thickness gauge 2 is moved to the edge portion of the object 20 to be measured. It is moved to 22 (point 104). Scanning thickness gauge 2
Starts measuring the thickness of the edge portion 22 of the DUT 20 from the point 104. The fixed thickness gauge 1 continues to measure the thickness of the central portion 21 of the DUT 20 as it is.

The operation correction unit 52 of the profile operation unit 5 is
From the measurement data of the central portion 21 by the scanning thickness gauge 2, the measurement data of the edge portion 22 by the fixed thickness gauge 1, and the measurement machine difference of the measurement machine difference calculator 51 obtained previously, the following equation (4) is obtained. The crown amount C is obtained as shown in.

C = Xc−Xe−dX (4) Here, Xc is the measurement data of the central portion 21 of the scanning thickness gauge 2, Xe is the measurement data of the edge portion 22 of the fixed thickness gauge 1, dX is the measurement instrument difference calculated by the measurement instrument difference calculation unit 51.

The crown amount C obtained as described above is
Since the measuring instrument difference between the fixed type thickness meter 1 and the scanning type thickness meter 2 is corrected, the value is highly accurate.

As described above, first, the thicknesses of the same position of the moving object to be measured are measured by the respective thickness gauges to obtain the measuring instrument difference between the respective thickness gauges, and then the respective thickness gauges of the predetermined locations are measured. By measuring the thickness and correcting the previously determined measurement machine difference from the measured data and calculating the crown amount, the measurement machine difference can be measured or registered periodically when offline. It is possible to obtain the crown amount C that saves labor and has high accuracy.

Another embodiment according to the present invention will be described with reference to FIGS. FIG. 3 is a block diagram showing this embodiment, and FIG. 4 is a fixed thickness gauge 1 of this embodiment and the first and second scanning thickness gauges when the object to be measured 20 is conveyed in the direction of the arrow. Two
This is for explaining the scanning positions of a and 2b.

This embodiment is for obtaining the amount of crown and the amount of wedge, and the configuration thereof is the same as that described in the conventional profile measuring device (see FIG. 7). In addition, a measuring machine difference calculation unit 51A and a calculation correction unit 52A are newly provided.

Before the measurement, the fixed thickness gauge control unit 3 and the first and second scanning thickness gauges 2a and 2b of the present embodiment are on the extension line of the central portion 21 of the object 20, that is, on the rolling line. It is located in the center (point 105). When the moving object 20 to be measured plunges into this (point 106), the fixed-type thickness gauge 1 detects the existence of the measured object 20, and the profile calculator 5A detects this through the fixed-type thickness gauge controller 3. To notify. At the same time, the fixed thickness gauge control unit 3 controls the measured object 20.
The thickness of the central portion 21 is measured, and the measurement data is transmitted to the measuring machine difference calculation unit 51A of the profile calculation unit 5A via the fixed thickness gauge control unit 3. The first and second scanning type thickness gauges 2a and 2b also measure the thickness of the central portion 21 of the object to be measured 20 and use the measured data as the first and second scanning type thickness gauge control units 4a and 4b, respectively. Is transmitted to the measuring instrument difference calculation unit 51A of the profile calculation unit 5A via.

Measuring instrument difference calculator 5 of profile calculator 5A
1A is a fixed type thickness gauge 1 until a certain time elapses after receiving a notification from the fixed type thickness gauge 1 that the object 20 to be measured is detected, that is, while the measurement target 20 is in the section d of FIG.
And continues to receive the measurement data from the first and second scanning thickness gauges 2a and 2b. The measuring instrument difference computing unit 51A of the profile computing unit 5A performs a process of averaging these data, and the measuring instrument difference dX1 of the fixed type thickness gauge 1 and the first scanning type thickness gauge 2a and the fixed type thickness gauge 1 are calculated from the following equations. The measuring instrument difference dX2 between the thickness meter 1 and the second scanning thickness meter 2b is calculated and stored.

DX1 = Xs1−Xf (5) dX2 = Xs2−Xf (6) where Xs1 is the measurement data of the first scanning type thickness gauge 2a, and Xs2 is the measurement data of the second scanning type thickness gauge 2b. It is measurement data, and Xf is measurement data of the fixed thickness gauge 1.

The profile calculation unit 5A activates the first scanning type thickness gauge control unit 4a at the time when the certain time has elapsed (point 107 in FIG. 4), and measures the first scanning type thickness gauge 2a. The edge 23a of the object 20 is moved to a point 108a which is inside a certain distance from the edge 23a on the drive side, and the second scanning type thickness gauge control unit 4b is activated to move the second scanning type thickness gauge 2b to the operator side of the object 20 to be measured. From the edge 23b to the point 108b. First and second scanning thickness gauge 2
a and 2b move to the points 108a and 108b, respectively, and then measure the thickness of the edge portions 22a and 22b of the object to be measured 20, and the respective measurement data Xd and Xo are controlled by the first and second scanning thickness gauge controls. It is sent to the operation correction unit 52A of the profile operation unit 5A via the units 4a and 4b. Fixed type thickness gauge 1
Continuously measures the thickness of the central portion 21 of the object to be measured 20, and sends the measurement data Xc to the calculation correction unit 52A of the profile calculation unit 5A via the fixed thickness gauge control unit 3.

Calculation correction section 52A of profile calculation section 5A
Shows these measurement data and the previously calculated measuring instrument difference calculation 51.
Based on the measurement instrumental differences dX1 and dX2 of A, the following equation (7),
As shown in (8), the crown amount C and the wedge amount W are obtained.

C = Xc-{(Xd-dX1) + (Xo-dX2)} / 2 (7) W = (Xo-dX2)-(Xd-dX1) (8) Crown amount obtained as described above C and wedge amount W
Is a fixed type thickness gauge 1 and a first and second scanning type thickness gauge 2
Since the measurement instrumental difference between a and 2b and the measurement instrumental difference between the first scanning type thickness gauge 2a and the second scanning type thickness gauge 2b are also corrected, they are highly accurate values. .

As described above, first, each thickness gauge measures the thickness of the moving object to be measured at the same location to obtain the measuring instrument difference of each thickness gauge, and then each thickness gauge determines the thickness of the predetermined location. By measuring and measuring the crown amount and wedge amount in consideration of the previously determined measurement device difference from the measurement data, the measurement device difference is regularly measured when offline, and the measurement device difference is registered. It is possible to save the labor and to obtain the crown amount and the wedge amount with high accuracy.

[0046]

According to the present invention, it is possible to provide a profile measuring apparatus capable of accurately and efficiently measuring profile data of an object to be measured.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a profile measuring device according to the present invention.

FIG. 2 is a diagram for explaining scanning positions of a fixed thickness gauge and a scanning thickness gauge according to an embodiment of the present invention.

FIG. 3 is a block diagram showing another embodiment according to the present invention.

FIG. 4 is a diagram showing a fixed type thickness gauge according to another embodiment of the present invention and a first type;
6A and 6B are views for explaining a scanning position with respect to a second scanning type thickness gauge.

FIG. 5 is a block diagram showing a profile measuring device according to a conventional technique.

FIG. 6 is a diagram for explaining scanning positions of a fixed thickness gauge and a scanning thickness gauge according to a conventional technique.

FIG. 7 is a block diagram showing another profile measuring device according to the prior art.

FIG. 8 is a diagram for explaining scanning positions of a fixed-type thickness gauge and first and second scanning-type thickness gauges according to a conventional technique.

[Explanation of symbols]

 1 Fixed type thickness gauge 2, 2a, 2b Scanning type thickness gauge 3 Fixed type thickness gauge control section 4, 4a, 4b Scanning type thickness gauge control section 5, 5A Profile calculation section 6 Display section 20 Measured object 21 Measured object Central part 22, 22a, 22b Edge part of measured object 23, 23a, 23b Edge of measured object 51, 51A Measuring machine difference calculation part 52, 52A Calculation correction part

Claims (2)

[Claims] 1. A first thickness gauge for measuring the thickness of the central portion of the object to be measured, and a second thickness gauge for measuring the thickness of the edge portion of the object to be measured. In the profile measuring device for measuring the profile of the object to be measured based on the measurement data of the second thickness meter, the first thickness meter and the second thickness meter are provided with the same position of the object to be measured for a predetermined time. The thickness is measured, and after the lapse of the predetermined time, the first thickness gauge is made to measure the thickness of the central portion of the measured object, and the second thickness gauge is made to measure the thickness of the edge portion of the measured object. And control means for controlling the first thickness gauge and the second thickness gauge from the measurement data measured by the first thickness gauge and the second thickness gauge during the fixed time. A measuring machine difference calculating unit for obtaining a machine difference, and the first machine after the predetermined time has elapsed See meter and profile measuring apparatus characterized by comprising a profile calculating means and a calculation correction unit for calculating a crown amount by correcting the measuring difference from the measured measurement data by the second thickness gauge. 2. A first thickness gauge for measuring the thickness of the central portion of the object to be measured, and second and third thickness gauges for measuring the thickness of the edge portions on both sides of the object to be measured. In the profile measuring device for measuring the profile of the object to be measured based on the measurement data of the first to third thickness gauges, the object to be measured is added to the first, second, and third thickness gauges. The thickness of the same place is measured for a certain period of time, and after the lapse of the certain period of time, the first thickness meter is made to measure the central portion of the measured object, and the second and third thickness meters are measured of the measured object. Control means for controlling to measure the edge portions on both sides respectively, and the first thickness gauge and the second thickness gauge based on the measurement data measured for a certain time by the first, second and third thickness gauges. Measuring instrument difference between the thickness gauges and the first thickness gauge A measuring instrument difference calculation unit that obtains a second measuring instrument difference between the third thickness gauges, and the measurement data measured by the first, second, and third thickness gauges after the elapse of the certain time. A profile measuring device comprising: a profile calculating unit having a calculation correcting unit that calculates a crown amount and a wedge amount by correcting a difference between a first measuring instrument and a second measuring instrument.